Assessing Whether an Invention Is Worth Filing At All
Protection costs the same whether the product sells ten units or ten million. The arithmetic that separates those outcomes can be done long before a drawing is finalised.
The uncomfortable feature of patent economics is that the expense is front-loaded and the revenue, if it comes at all, is not. Filing, examination and renewal fall due on a schedule that pays no attention to whether a single unit has been sold. An invention that will earn nothing costs almost exactly as much to protect as one that will earn a great deal.
That asymmetry is why the assessment belongs at the start. It is not a matter of confidence or pessimism; it is arithmetic that can be done in an afternoon with numbers an inventor can obtain by asking. Most of the work involves four questions: what the thing costs to make at a realistic volume, what a buyer will actually pay, who stands between the two, and how long the advantage lasts once a competitor decides to respond.
The four inputs
- Landed unit cost
- Tooling amortised, materials, labour, packaging and freight — not the cost of the hand-built prototype.
- Shelf price
- What the comparable product on sale today costs, which is the ceiling a buyer has already been trained to expect.
- Channel take
- The share absorbed between factory and buyer by distributors and retailers before anything reaches the inventor.
- Response time
- How long a competent competitor needs to design around the claims and reach the same shelf.
One · The Floor
The Margin a Physical Product Has to Clear
Consumer products travel through a chain, and each link takes a share. By the time an item made for a given unit cost reaches a buyer, the price has typically multiplied several times over: once when the manufacturer sells to a distributor, again when the distributor sells to a retailer, and again at the shelf. The multiple varies by category, but the direction never does — the inventor sits at the far end of that chain, and whatever remains after everyone else has taken their share is what a royalty is calculated on.
This is the arithmetic that quietly settles most questions of commercial viability before any legal question arises. If the honest landed cost is close to the price of the product already on the shelf, there is no room in the chain for a new entrant, and no amount of patent protection creates room. If the cost is a small fraction of the shelf price, there is space for margin, for the channel, and for a royalty that a licensee will not resent paying.
Prototype cost is the most common source of error here. A hand-assembled first article says almost nothing about volume cost, and inventors routinely over-estimate in one direction and under-estimate in the other. Tooling is a fixed cost recovered across a production run, so the useful figure is always cost at a plausible annual volume — a number a contract manufacturer will usually quote from a dimensioned drawing without charge.
A patent can stop a competitor. It cannot create margin that the price of the product never contained.
The floor, stated plainly
Two · The Buyer
Who Actually Has the Problem, and How Badly
The second question is narrower than market size and considerably more useful. Rather than asking how many people might conceivably buy the product, ask who currently experiences the problem often enough to have improvised a workaround. Improvised workarounds are the strongest available evidence of demand: someone has already paid in effort what they were unwilling to pay in money, which means the willingness is there and only the price and availability are unsettled.
Categories with clear, repeated, personal frustrations tend to produce the most durable independent inventions, and the record bears that out. The account of how one everyday kitchen frustration became a product follows the familiar shape: a specific, repeated annoyance; a mechanism simple enough to manufacture at a sane cost; and a category where buyers already accept a certain price point. None of those three is about brilliance, and all three are about fit.
The inverse pattern is worth naming too. An invention that solves a problem people encounter twice a year, or that requires the buyer to change an established habit before the benefit appears, faces a demand curve so shallow that even a strong patent position generates little. Adoption friction is a cost like any other; it is simply paid in persuasion rather than in materials.
Three · The Constraints
Manufacturing and Compliance Set the Ceiling Early
Two constraints are established at the design stage and are expensive to revisit afterwards. The first is manufacturability: a part that must be machined rather than moulded, a mechanism with a dozen components where a competitor's has four, an assembly step requiring skilled hands — each pushes the unit cost up permanently. Design for manufacture is not a later refinement. It is a determinant of whether the margin arithmetic ever works.
The second is regulatory exposure. Products that contact food or skin, carry mains current, make a health claim, or are intended for children face testing and certification regimes that add both cost and calendar time. That is not a reason to avoid those categories — barriers deter competitors as well — but the cost belongs in the assessment from the beginning rather than arriving as a surprise after tooling is committed.
Materials choices increasingly carry the same weight. Where a category is moving toward recycled or lower-impact inputs, a design specified around a material that a manufacturer expects to phase out inherits an obsolescence problem. Coverage of the rise of environmentally driven invention reflects a shift visible in procurement across many categories: material specification has become a commercial decision, not only a technical one.
Four · The Licensee
What a Company Is Actually Buying
Most independent inventions reach a shelf through a licence rather than a manufacturing business built from nothing, so it is worth understanding what the counterparty is evaluating. A licensee is not buying an idea. It is buying a defensible position in a category it already serves, with tooling it can specify, at a unit cost that fits its existing margin structure, protected by claims broad enough that a competitor cannot reproduce the benefit with a trivial variation.
Each of those requirements maps back to a decision the inventor makes early. Claim scope depends on the search and the drafting. Unit cost depends on the design. Category fit depends on which problem was chosen. A licensing conversation is largely an audit of decisions already taken months earlier, which is why an assessment of commercial viability conducted at the outset tends to produce better licensing terms than one conducted after a prototype exists.
The same logic applies well beyond consumer goods. In fields where the end user is a professional buyer, the evaluation is more formal but the substance is identical — cost, fit, defensibility and time to respond. Discussion of inventor-led design in the built environment describes the same audit applied to specification-driven products, where the buyer is a professional and the response time is measured in project cycles rather than seasons.
Five · The Verdict
When the Honest Answer Is No
An assessment that cannot return a negative answer is not an assessment. Some inventions fail the arithmetic: the cost sits too close to the shelf price, the problem is too rare, the design-around is too easy, or the category moves faster than examination does. Reaching that conclusion in month one costs a few weeks of thought. Reaching it in year three costs the filing, the drafting, the prosecution and the renewals, and it usually arrives by way of a licensee's polite decline.
A negative verdict is also rarely final. The most common outcome of a serious viability review is not abandonment but redirection: the same mechanism aimed at an industrial buyer instead of a consumer one, the same principle simplified to fewer parts, or the same insight applied to the adjacent problem where the workaround is more painful. The four attrition points that stop most projects, set out in the main report on why ideas stall before filing, are all easier to clear once the commercial question has been settled honestly.
The purpose of the exercise is not to be discouraging. It is to make sure the budget is still intact when an idea that deserves it finally arrives.
End of report
Decided early, viability is a research question. Decided late, it is an autopsy.
On timing